Acoustic wave sensors are utilized in a variety of sensing applications, such as, for example, temperature and/or pressure sensing devices and systems. Examples of surface wave sensors include devices such as acoustic wave sensors, which can be utilized to detect the presence of substances, such as chemicals. An acoustical or acoustic wave (e.g., SAW/BAW) device acting as a sensor can provide a highly sensitive detection mechanism due to the high sensitivity to surface loading and the low noise, which results from their intrinsic high Q factor. Surface acoustic wave devices are typically fabricated using photolithographic techniques with comb-like interdigital transducers placed on a piezoelectric material. Surface acoustic wave devices may have either a delay line or a resonator configuration.
One application where surface acoustic wave (SAW) sensors have been utilized effectively involves pressure and/or temperature sensing of vehicle tires. Tire pressure sensors have been assembled in a configuration in which a SAW die floats on a base to which the SAW die is eventually wirebonded. One of the problems with such a configuration is that the SAW die typically does not remain centered during the wirebonding assembly, resulting in poor yields.